The present invention relates to automotive safety systems and, more particularly, concerns an adaptive occupant protective system for vehicles equipped with bumper-bag systems.
Current vehicle crash safety systems typically employ accelerometers that measure decelerations acting on the vehicle body during a crash event. In response to signals from such accelerometers, airbags or other safety devices are activated. In certain crash situations, however, it is desirable to provide information before forces actually act upon the vehicle such as when a collision is unavoidable. Such systems are commonly known as collision prediction systems or pre-crash warning systems. Such remote sensing applications use radar, lidar, or vision-based technologies for collision avoidance and pre-collision warning applications.
With regard to occupant safety systems, in addition to conventional airbags within the passenger compartment, exterior airbag systems are also being considered for vehicle applications. These exterior airbag applications are commonly referred to as xe2x80x9cbumper-bagxe2x80x9d applications, when the bags are located along the exterior of the vehicle near the front or rear bumpers.
Bumper-bag systems are most effective when they are fully deployed before actual physical contact with the impacting object. Accordingly, unlike interior occupant airbags, bumper-bags are most likely to be deployed in response to pre-crash sensing information.
When bumper-bags are deployed in a crash situation, however, they can change the collision dynamics of the vehicle which would otherwise occur by acting as an additional energy-absorbing component and by providing additional collapsible distance. These changes in the collision dynamics can affect the host vehicle crash pulse as seen by the accelerometers, the crash duration, the amount of passenger compartment deformation, and other occupant injury-producing phenomena.
Bumper-bag systems, however, are not deployed in all crash situations. For example, to minimize repair costs, bumper-bags may not be deployed in relatively low-velocity impact situations. Also, due to real-time performance limitations of the pre-crash sensing systems, bumper-bags may not be deployed in crash situations with very high relative velocities between the impacting and host vehicle, or when the pre-crash sensing system cannot xe2x80x9cseexe2x80x9d the impacting object such as, for example, during a high speed intersection-type collision.
Accordingly, it is desirable to optimize the performance of the occupant safety systems, and the vehicle interior occupant airbags in particular, under both situations when the bumper-bags are deployed and are likely to alter the collision dynamics, and when the bumper-bags have not been deployed and the crash situation is equivalent to a vehicle without a bumper-bag system. The present invention is directed towards providing such an adaptive safety system for bumper-bag equipped vehicles.
An adaptive safety system for bumper-bag equipped vehicles in accordance with one embodiment of the present invention includes a safety system control method for a host automotive vehicle. The method comprises providing a first vehicle safety countermeasure and providing a second vehicle safety countermeasure operable in a first mode corresponding to the first vehicle safety countermeasure being inactive and a second mode corresponding to the first vehicle safety countermeasure being activated. The method also determines a collision threat with a target object and selectively activates the first vehicle safety countermeasure as a function of the collision threat. The second vehicle safety countermeasure is then activated in the second mode when the first vehicle safety countermeasure is activated. Otherwise, the second vehicle safety countermeasure is activated in the first mode when the first vehicle safety countermeasure is inactive. The first vehicle safety countermeasure can be an external vehicle airbag and the second vehicle safety countermeasure can be in internal occupant airbag.
In another embodiment, a safety system control method for a host automotive vehicle including at least one external vehicle airbag and at least one internal occupant airbag is provided. The method includes determining a collision threat with a target object, selectively activating the external vehicle airbag as a function of the collision threat, and, in response to a crash event, activating at least one internal occupant airbag in a first mode when the external vehicle airbag is activated, otherwise, activating the at least one internal occupant airbag in a second mode when the external vehicle airbag is inactive.
In anther embodiment, a safety system for an automotive vehicle having a pre-crash sensing system is provided. The system includes a first vehicle safety countermeasure, a second vehicle safety countermeasure operable in a first mode corresponding to the first vehicle safety countermeasure being inactive and a second mode corresponding to the first vehicle safety countermeasure being activated, and a controller coupled to the pre-crash sensing system and the first and second vehicle safety countermeasures. The controller determines a collision threat with a target object, selectively activates the first vehicle safety countermeasure as a function of the collision threat, and activates the second vehicle safety countermeasure in the second mode when the first vehicle safety countermeasure is activated.
The present invention is advantageous in that it can provide improved occupant protection by optimizing the response characteristics of the occupant safety systems in response to likely changes in vehicle collision dynamics resulting from bumper-bag or other countermeasure deployment.
Other advantages and features of the invention will become apparent to one of skill in the art upon reading the following detailed description with reference to the drawings illustrating features of the invention by way of example.